Evolutionary biologist Lynn Margulis dies at 73

Scientist Richard Dawkins called her theory “one of the great achievements of twentieth-century evolutionary biology.”

On November 22, 2011, Lynn Margulis died at the age of 73, five days after suffering a hemorrhagic stroke from which she never regained consciousness. She was Distinguished University Professor in the Department of Geosciences at the University of Massachusetts, Amherst, was elected to the National Academy of Sciences in 1983, in 1999 received the Presidential Medal of Science from Bill Clinton, and was a member of the American Academy of Arts and Sciences.

Admitted to the University of Chicago at age fourteen, her prodigious career included marrying fellow scientist Carl Sagan at age nineteen. Margulis’s first book, The Origin of Eukaryotic Cells (Yale University Press, 1970), announced her path-breaking endosymbiotic theory of the evolution of the eukaryotic cell from the interdependence and cooperative existence of multiple prokaryotic organisms. She was often critical of versions of neo-Darwinist orthodoxy that stressed a “zoological, capitalistic, competitive, cost-benefit interpretation of Darwin.” Rejected for years by mainstream scientific orthodoxy, her theory of endosymbiosis stressed instead complex forms of cooperation and co-existence, and is now considered textbook biology on the role of symbiosis in early evolution. Fellow scientist Richard Dawkins called her theory “one of the great achievements of twentieth-century evolutionary biology.”

Later, Margulis lent her support, scientific and otherwise, to English environmental scientist James Lovelock and his famous Gaia theory, which is now broadly accepted in Earth System Science, resulting in volumes by Margulis such as Slanted Truths: Essays on Gaia, Symbiosis, and Evolution (1997) and Symbiotic Planet : A New Look at Evolution (1998). Her late work moves ever more boldly between scientific observation and hypothesis and social and cultural context, serving for many as a model and inspiration for interdisciplinary scholarship. In the 1980s, Margulis began to co-author works with her son, Dorion Sagan, who wrote the introduction to the Jakob von Uexkϋll volume A Foray into the Worlds of Animals and Humans. Over the years, she and Dorion explored a wide range of topics, from the evolution of human sexuality to the “subvisible” world of microbial life. Our thoughts go out to Dorion and the rest of the family at this difficult time as we remember and celebrate the life and work of Lynn Margulis.